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标题：Photothermoelectric and photovoltaic effects both present in MoS2
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作者：Youwei Zhang ; Hui Li ; Lu Wang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep07938
语种：English
出版社：Springer Nature
摘要：As a finite-energy-bandgap alternative to graphene, semiconducting molybdenum disulfide (MoS₂) has recently attracted extensive interest for energy and sensor applications. In particular for broad-spectral photodetectors, multilayer MoS₂ is more appealing than its monolayer counterpart. However, little is understood regarding the physics underlying the photoresponse of multilayer MoS₂. Here, we employ scanning photocurrent microscopy to identify the nature of photocurrent generated in multilayer MoS₂ transistors. The generation and transport of photocurrent in multilayer MoS₂ are found to differ from those in other low-dimensional materials that only contribute with either photovoltaic effect (PVE) or photothermoelectric effect (PTE). In multilayer MoS₂, the PVE at the MoS₂-metal interface dominates in the accumulation regime whereas the hot-carrier-assisted PTE prevails in the depletion regime. Besides, the anomalously large Seebeck coefficient observed in multilayer MoS₂, which has also been reported by others, is caused by hot photo-excited carriers that are not in thermal equilibrium with the MoS₂ lattice.